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RSS1999 Vol. 23, No. 2
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1999, 23(2): 65-67.
[Abstract]
[PDF 230KB]
Abstract:
A simulated set up of high-speed simulated exhaust muzzle flow field is made up.Moir deflectometry is used to display and quantitatively measure jet flow field of bi-based power muzzle.The system consists of laser source,Moir deflectometer,CCD,monitor,image store and processor and 586 computer.Using Moir deflectometry and tomography the distribution of temperature of flow field is visualized and calculated quantitatively.
A simulated set up of high-speed simulated exhaust muzzle flow field is made up.Moir deflectometry is used to display and quantitatively measure jet flow field of bi-based power muzzle.The system consists of laser source,Moir deflectometer,CCD,monitor,image store and processor and 586 computer.Using Moir deflectometry and tomography the distribution of temperature of flow field is visualized and calculated quantitatively.
1999, 23(2): 68-70.
Abstract:
A innovatory avoidance adjust solid state laser was demonstrated.It used the directional prism as a reflector of the resonant cavity.With the prism reflector,the laser operats normally without special adjustment.The stability is the highest than other rasonant cavity.The divergence angle of laser beam is small.The laser energy of far-field is focus.The deflection angle allowed of the reflector is of ±20°.The laser rod shift of D/4 is allowed which D is the diameter of the laser rod.The divergence angle of laser beam is small than 3 mrad.The laser output energy 300mJ/pulse in the high repeatition of 100Hz with a Cr4+:YAG crystal as passive Q-switch,and the laser field distribution is homogeneous.
A innovatory avoidance adjust solid state laser was demonstrated.It used the directional prism as a reflector of the resonant cavity.With the prism reflector,the laser operats normally without special adjustment.The stability is the highest than other rasonant cavity.The divergence angle of laser beam is small.The laser energy of far-field is focus.The deflection angle allowed of the reflector is of ±20°.The laser rod shift of D/4 is allowed which D is the diameter of the laser rod.The divergence angle of laser beam is small than 3 mrad.The laser output energy 300mJ/pulse in the high repeatition of 100Hz with a Cr4+:YAG crystal as passive Q-switch,and the laser field distribution is homogeneous.
1999, 23(2): 71-76.
Abstract:
So far,many alkali halide ionic excimers(AX)+,rare gas alkali ionic excimers(RgA)+,rare gas halide ionic excimers(RgX)+,heteronuclear and isonuclear rare gas ionic excimers as wel as the optical gain in Cs2+F- ionic excimer and the oscillation of argon ionic excimers have been observed.This paper describes the development of the research on these excimers from the point of view of spectroscopy and kinetics and indicates that rapid and uniform pumping with high strength and large size is the key to realization of population reversion of ionic excimers.
So far,many alkali halide ionic excimers(AX)+,rare gas alkali ionic excimers(RgA)+,rare gas halide ionic excimers(RgX)+,heteronuclear and isonuclear rare gas ionic excimers as wel as the optical gain in Cs2+F- ionic excimer and the oscillation of argon ionic excimers have been observed.This paper describes the development of the research on these excimers from the point of view of spectroscopy and kinetics and indicates that rapid and uniform pumping with high strength and large size is the key to realization of population reversion of ionic excimers.
1999, 23(2): 77-79.
Abstract:
Photophysics of excited state and optical limiting in new N-acetamide C60 nitride (N-acetamide 1,2-dihydro-1,2-aza-fullerene[60]) are experimentally studied.Comparing with the optical limiting properties of fullerene,these new materials have better optical limiting characteristics in red light range.
Photophysics of excited state and optical limiting in new N-acetamide C60 nitride (N-acetamide 1,2-dihydro-1,2-aza-fullerene[60]) are experimentally studied.Comparing with the optical limiting properties of fullerene,these new materials have better optical limiting characteristics in red light range.
1999, 23(2): 79-81.
Abstract:
The hundred-watt transverse-flow CO2 laser is designed.The laser utilized the technique of gas transverse flow and longitudinal confined discharge to obtain the maximum discharge area and the uniform discharge property.V-A characteristic of the laser has been detected,and the V-A curve is a slow variation.In our system,the maximum discharge power is high up to 2440W,the quantum efficiency is 40%,the electron-photo transfer efficiency is 10%～20%.
The hundred-watt transverse-flow CO2 laser is designed.The laser utilized the technique of gas transverse flow and longitudinal confined discharge to obtain the maximum discharge area and the uniform discharge property.V-A characteristic of the laser has been detected,and the V-A curve is a slow variation.In our system,the maximum discharge power is high up to 2440W,the quantum efficiency is 40%,the electron-photo transfer efficiency is 10%～20%.
1999, 23(2): 82-86.
Abstract:
We have developed an engineering "eye-safe" CO2 laser rangefinder (LRF).It is based on a miniature metal-ceramic TEA CO2 laser operating at 10.6 micronmeters and CMT detector cooled by splitting close-cycle Stirling.The CO2 LRF has modular construction and diagnosing failures automati-cly,data storage and RS422 transmitt interface.Its operation is stable and reliable,easily matain and use.It have been succeeded in seriously checkout for enviromental suitability,examine of specifications and field test.The all specifications have sufficed requirements to usage and have been turned over to a comsumer.The article discribes the TEA CO2 LRF design configuration and its main specifications.
We have developed an engineering "eye-safe" CO2 laser rangefinder (LRF).It is based on a miniature metal-ceramic TEA CO2 laser operating at 10.6 micronmeters and CMT detector cooled by splitting close-cycle Stirling.The CO2 LRF has modular construction and diagnosing failures automati-cly,data storage and RS422 transmitt interface.Its operation is stable and reliable,easily matain and use.It have been succeeded in seriously checkout for enviromental suitability,examine of specifications and field test.The all specifications have sufficed requirements to usage and have been turned over to a comsumer.The article discribes the TEA CO2 LRF design configuration and its main specifications.
1999, 23(2): 86-90.
Abstract:
In this paper, the lightcraft vehicle without on-board chemical fuel was analyzed．Sending manned craft into space on satellite laser-beams powered by solar energy in next age was speculated.
In this paper, the lightcraft vehicle without on-board chemical fuel was analyzed．Sending manned craft into space on satellite laser-beams powered by solar energy in next age was speculated.
1999, 23(2): 91-94.
Abstract:
In this paper,some main intensity compensation techniques for sensing measuring using intensity fiber as optical sensor are presented.Especially,the fundamental principles,system configurations,functions and properties of the double path compensation techniques and single path compensation techniques are described in detail.The differences and relation of the double path compensation and single path compensation techniques are also analyzed.
In this paper,some main intensity compensation techniques for sensing measuring using intensity fiber as optical sensor are presented.Especially,the fundamental principles,system configurations,functions and properties of the double path compensation techniques and single path compensation techniques are described in detail.The differences and relation of the double path compensation and single path compensation techniques are also analyzed.
1999, 23(2): 95-98.
Abstract:
Based on cavity theory,the characteristics of dynamic stability zone of a parallel-concave laser cavity are analyzed in detail,taking account of thermal lens effect equivalent to convex lens.In general,the laser with parallel-concave cavity can operate in one of two dynamic stability zones.We found that,in a special case,the parallel-concave cavity has only one dynamic stability zone.According to theoretical analysis,we selected a set of cavity parameters and carried out the experiments,taking Nd:YAG as a exmple.The results show that the output power of laser increase with the pumping power in a rather wide range.
Based on cavity theory,the characteristics of dynamic stability zone of a parallel-concave laser cavity are analyzed in detail,taking account of thermal lens effect equivalent to convex lens.In general,the laser with parallel-concave cavity can operate in one of two dynamic stability zones.We found that,in a special case,the parallel-concave cavity has only one dynamic stability zone.According to theoretical analysis,we selected a set of cavity parameters and carried out the experiments,taking Nd:YAG as a exmple.The results show that the output power of laser increase with the pumping power in a rather wide range.
1999, 23(2): 99-104.
Abstract:
The far-field spot characteristics of laser converted by random phase plate are analyzed theoretically,including the shape,size,rotational symmetry and diffractive efficiency of the spots,as well as the distribution of subsidiary spot.By comparing the influence of phase element shape(triangular,square and hexagonal) on the characteristics,we found that the random phase plate with hexagonal array structure is more suitable for the beam smoothing in laser fusion.
The far-field spot characteristics of laser converted by random phase plate are analyzed theoretically,including the shape,size,rotational symmetry and diffractive efficiency of the spots,as well as the distribution of subsidiary spot.By comparing the influence of phase element shape(triangular,square and hexagonal) on the characteristics,we found that the random phase plate with hexagonal array structure is more suitable for the beam smoothing in laser fusion.
1999, 23(2): 104-108.
Abstract:
In this paper,starting from the generalized Huygens-Fresnel diffraction integral and B-integral definition,and based on the statistical-optics method,the nonlinear propagation properties of laser beams with amplitude modulations and phase fluctuations have been studied in detail.
In this paper,starting from the generalized Huygens-Fresnel diffraction integral and B-integral definition,and based on the statistical-optics method,the nonlinear propagation properties of laser beams with amplitude modulations and phase fluctuations have been studied in detail.
1999, 23(2): 109-113.
Abstract:
Based on two order approximation of the variation of refraction index produced by self-action while optical pulses are traveling in Kerr-medium,the propagation equation has been solved.Furthermore,the strict analytical expressions of the amplitude,width and chirp parameter of chirped Gaussian pulse,relative to the propagation distance,are deduced.The solitary wave traveling conditions of fundamental mode Gaussian pulse have been discussed.
Based on two order approximation of the variation of refraction index produced by self-action while optical pulses are traveling in Kerr-medium,the propagation equation has been solved.Furthermore,the strict analytical expressions of the amplitude,width and chirp parameter of chirped Gaussian pulse,relative to the propagation distance,are deduced.The solitary wave traveling conditions of fundamental mode Gaussian pulse have been discussed.
1999, 23(2): 113-115.
Abstract:
Based on linear frequency modulation continuous wave (FMCW) technique,we have developed a distance measurement method for non-contact and non-integrating error measurement.A tunable GaAlAs diode laser is used as a chirp signal source,the distance is detected by calculating the beat frequency.The dynamic range of the system is about 1m,and the measurement accuracy of 10-3 is obtained.
Based on linear frequency modulation continuous wave (FMCW) technique,we have developed a distance measurement method for non-contact and non-integrating error measurement.A tunable GaAlAs diode laser is used as a chirp signal source,the distance is detected by calculating the beat frequency.The dynamic range of the system is about 1m,and the measurement accuracy of 10-3 is obtained.
1999, 23(2): 116-118.
Abstract:
The compensative problem of laser trough is very important in laser carving. This paper analyses the mat hematical morphology essence of laser trough. In addition, it gives a changeable structuring element compensative algorithm. The algorithm has proved to be well in practice.
The compensative problem of laser trough is very important in laser carving. This paper analyses the mat hematical morphology essence of laser trough. In addition, it gives a changeable structuring element compensative algorithm. The algorithm has proved to be well in practice.
1999, 23(2): 119-122.
Abstract:
In this paper,we proposed a novel free electron laser(FEL), using two ultra-short laser pulses as a wiggler,instead of conventional wiggler coil.A single particle approach has been used to derive the gain equations at the fundamental harmonic in this construction.According to this proposal,it is possible to manufacture a compact a low-priced FEL.
In this paper,we proposed a novel free electron laser(FEL), using two ultra-short laser pulses as a wiggler,instead of conventional wiggler coil.A single particle approach has been used to derive the gain equations at the fundamental harmonic in this construction.According to this proposal,it is possible to manufacture a compact a low-priced FEL.
1999, 23(2): 122-125.
Abstract:
The thermal couples are useful detector in laser power or energy measurement or other areas.Now,we developed a novel thin film thermal couple detector deposited on high thermal conductive substrate.This paper described the manufacture parameters and the effects of construction on the response index,response time and noise of the thin film thermal couple detector.
The thermal couples are useful detector in laser power or energy measurement or other areas.Now,we developed a novel thin film thermal couple detector deposited on high thermal conductive substrate.This paper described the manufacture parameters and the effects of construction on the response index,response time and noise of the thin film thermal couple detector.
1999, 23(2): 126-128.
Abstract:
In order to improve the surface performance of A3 steel,we utilize a high power CO2 laser beam to treat the B4C-TiN-Co clad surface．It is obvious that the laser beam scanning speed is an important factor effecting on the microstructure,hardness and the resistance to abrasion of the alloy surface．This paper introduces the experimental research procedure,and the experimental results．These are useful to select the beam scanning speed and other technical parameters．
In order to improve the surface performance of A3 steel,we utilize a high power CO2 laser beam to treat the B4C-TiN-Co clad surface．It is obvious that the laser beam scanning speed is an important factor effecting on the microstructure,hardness and the resistance to abrasion of the alloy surface．This paper introduces the experimental research procedure,and the experimental results．These are useful to select the beam scanning speed and other technical parameters．
